Cardiac catheterization and angioplasty are common medical procedures. U.S. Pat. No. 5,484,412 describes an angioplasty procedure wherein a balloon dilatation catheter is movably positioned within an anchoring catheter, which in turn is located within a guiding catheter. Optionally, internal balloons in the anchoring catheter can be inflated to anchor it to the balloon dilatation catheter. External balloons on the anchoring catheter can be inflated to anchor it to the inside of the guiding catheter. The balloons can be selectively inflated and deflated. Other external balloons on the distal outer surface of the anchoring catheter can be inflated to secure the anchoring catheter within the blood vessel beyond the distal end of the guiding catheter. Optional perforations in the wall of the anchoring catheter permit blood to enter and exit, especially while external balloons are inflated.
Using the anchoring catheter during an angioplasty procedure, the conventional guiding catheter is first inserted into the blood vessel to a location proximal to the narrowing targeted for treatment. The conventional guidewire, balloon dilatation catheter, and anchoring catheter are then inserted through the guiding catheter with the anchoring catheter and balloon dilatation catheter optionally being secured together by the internal balloons on the anchoring catheter. When the guidewire, dilatation catheter and anchoring catheter exit the distal end of the guiding catheter, the internal balloons are collapsed, if they were inflated, and the spaced external balloons are inflated to secure the anchoring catheter to both the guiding catheter and the interior of the blood vessel. The balloon dilatation catheter is then extended through the end of the anchoring catheter to perform its conventional function with respect to the narrowed section of the blood vessel.
Despite this advancement in the art, problems still remain. In U.S. Pat. No. 5,484,412, the entry point of the guidewire and balloon dilatation catheter into the anchoring catheter is at the proximal end of the anchoring catheter. Consequently, it is difficult to maintain the position of the guidewire down the coronary artery while loading the anchoring catheter onto the back end of the guidewire. Also, by having the entry point of the guidewire and balloon dilatation catheter at the proximal end of the anchoring catheter, the guidewire must extend through the entire catheter. If the anchoring catheter is loaded on the back of the guidewire, the guidewire would have to be withdrawn or extended in length until the wire extended out the back end of the anchoring catheter to allow the operator to grasp the guidewire while advancing the anchoring catheter. Furthermore, if the anchoring catheter needs to be withdrawn or exchanged, it is difficult to hold the guidewire in place without extending it or exchanging it for an exchange-length guidewire. It is important for the operator to have control of the guidewire during advancement or retraction of the balloon dilatation catheter and/or the anchoring catheter so as not to lose the guidewire position in the vessel being treated.
Known in the art are a variety of means for inserting a guidewire through the side of a balloon dilatation catheter. Examples of such devices are disclosed in U.S. Pat. Nos. 5,489,271 and 5,554,118. While these devices assist in inserting or exchanging a balloon dilatation catheter, they do not incorporate the use of or the advantages associated with the use of an anchoring catheter to maintain the position of the guidewire, the balloon dilatation catheter, and the guiding catheter within the coronary artery.
Thus, a primary object of the present invention is to provide an angioplasty catheter assembly that has an anchoring catheter with an opening in its side wall so that the guidewire and balloon dilatation catheter may extend there through.
Another object of the present invention is to provide an angioplasty catheter assembly that allows for a guidewire to be maintained in its position down the coronary artery.
Yet another object of the present invention is to provide an angioplasty catheter assembly that does not cause the guidewire to have to be withdrawn, extended or exchanged for a longer guidewire to allow the operator to grasp the guidewire while advancing an anchoring catheter.
Another object of the present invention is to provide an angioplasty catheter assembly that helps prevent the loss of the guidewire position within the coronary artery.
Another object of the present invention is to provide an angioplasty catheter assembly having a longitudinal slit along the anchoring catheter to allow an operator to extend the guidewire through the tubular wall of the anchoring catheter at multiple positions.
These and other objects, features, or advantages of the present invention will become apparent from the specification and claims. Although some descriptions of the invention refer to angioplasty systems, dilatation balloons, balloon dilatation catheters and treatment of coronary arteries, it should be understood that such elements are merely exemplary and the invention can be used in conjunction with a variety of treatment catheters and in different vessels of the human body. Treatment catheters can include treatment elements such as, for example, angioplasty balloons, stents and stent delivery components and radiation therapy apparatuses.